1. UC IPM
Blackline disease, <i>Cherry leafroll virus</i>, in English walnut on Paradox rootstock spreads from the graft union downward as a canker as shown here by removing bark.
Blackline disease, Cherry leafroll virus, in English walnut on Paradox rootstock spreads from the graft union downward as a canker as shown here by removing bark.
Credit: John M. Mircetich